A program of research on aging and the quality of human sleep is proposed, with primary attention to possible changes in the depth or soundness of sleep in the various EEG stages as measured by auditory awakening thresholds. Whether the auditory awakening threshold in delta sleep in the elderly remains deeper than in other stages will be assessed, along with an evaluation of the effect of exercise on the soundness of sleep in the elderly. Exploratory studies also to be conducted are: the level of physiological arousal in "good" and "poor" elderly sleepers compared to previous findings in young adults; and the effect of exercise by the elderly on physiological arousal during sleep and the amplitude of delta activity in the sleep EEG; and a questionnaire study on relationships between sleep, exercise, and morale in the elderly.